A dead bolt lock assembly usually includes a cylinder for receiving a key on a first side of a door and a turn piece on a second side of the door. Both the turn piece and the cylinder are operable for extending and retracting a dead bolt from a door into a door jamb. When the dead bolt is operated by a key in the cylinder on the first side of the door, the turn piece on the second side of the door is rotated. At times it is desirable to prevent rotation of the turn piece so that the lock may not be operated from the first side of the door.